THE GROUND BEETLES. 



71 



alutaceous, finely rugose at base, the basal impressions broad, deep, bistri- 

 ate. Elytra about one-half wider than thorax, the intervals less convex 

 than in coxendix. Length 4.5-6.5 mm. 



Throughout the State ; frequent ; more so in the northern coun- 

 ties. May 1 -September 4. Listed as B. nitidulum Dej., which 

 name was preoccupied. Resembles coxendix, but easily separated 

 by the pale legs and green punctures of elytra. 



Group B. 



In this group the dorsal punctures are on the third stria instead 

 of the interval and the humeri are either rounded or subangulate. 

 It includes the Indiana species of Groups Y to X of Hayward. 



KEY TO INDIANA SPECIES OF GROUP B. 



a. Eighth stria of the elytra moderately near but distinct from the margin. 

 h. Humeri of elytra subangulate; elytra 1 striae entire. 



c. Elytra with the dorsal punctures large, round impressions ; elytra 

 finely striate, shining. 81. americanum. 



cc. Elytra with the dorsal punctures normal. 



d. Form broad, dilated, depressed; hind angles of thorax obtuse; 

 size larger, 0.5-7.2 mm. dilatatum. 

 dd. Form more or less convex and more slender ; hind angles of 

 thorax subrectangular ; size smaller, 5.5-6.5 mm. 

 c. Feebly convex ; thorax scarcely narrower at base than apex ; 



elytral striae moderately impressed. 82. honestum. 



ee. More convex ; thorax more narrowed behind ; elytral striae 

 more deeply impressed, almost crenulately punctate. 



83. chalceum. 



bh. Humeri of elytra rounded; robust, very convex; elytral striae di- 

 lated, the first and second entire, the others abbreviated behind ; 

 blackish-bronzed, the elytra often tinged with green. S4. nigrum. 

 da. Eighth stria of elytra indistinct from margin; humeri rounded. 



f. Thorax trapezoidal, scarcely convex, the basal fovea with either one 

 stria or with two and the outer one very feeble ; legs rufous or 

 dull yellow, the femora rarely darker. 

 g. Basal impressions of thorax with the outer stria small but dis- 

 tinct ; size smaller. 4.8-6.2 mm. 

 /?. Elytra with five inner striae only entire; thorax one-half wider 

 than long. 85. guexi. 



lih. Elytra with six inner striae entire; thorax more than one-half 

 wider than long; the elytra less wide as compared with the 

 thorax ; color nearly black, tinged with bronze. fugax. 

 gg. Basal impressions of the thorax with the outer stria obsolete : 

 elytra with six inner striae entire, their color variable, usually 

 dull yellow with darker transverse bands ; size larger. 6-S.5 mm. 



TRANS VERS ALE. 



